Burma's highest court has rejected an appeal to allow more defense witnesses in the trial of detained democracy leader Aung San Suu Kyi. The trial has been widely condemned as rigged to keep the Nobel Peace Prize winner locked up.

The Burmese high court on Monday ruled against allowing two more defense witnesses.

The decision upheld a ruling by a lower court banning Win Tin and Tin Oo from testifying on her behalf.

The men are senior members of Aung San Suu Kyi's National League for Democracy party and critics of Burma's military government.

Nyan Win is a spokesman for the NLD and is also one of Aung San Suu Kyi's lawyers. He says the decision demonstrates that the trial is rigged.

"We always mentioned about this … the trial is not fair because, first, it's not a public hearing. And, then we submit four defense witnesses but the court permit one witness and then divisional court another witness," he said. "So, at that time the prosecutor side has testified 15 witnesses. This is very glaring that there is no fair trial."

The high court's rejection comes just after the United Nations special envoy, Ibrahim Gambari, visited Burma.

He spoke with Burmese officials about a possible visit next month by U.N. Secretary-General Ban Ki-moon.

The U.N. wants Burma's military government to release Aung San Suu Kyi and more than 2,000 other political prisoners.

Mr. Ban is said to be considering if his presence in the country would help win their freedom or be used as propaganda.

Nyan Win says the NLD would welcome a visit by Mr. Ban, but says the U.N. must increase the pressure on Burma's rulers.

"We welcome always the U.N. effort," he said. "The result is good for democracy or not, is another thing."

Burma's military has ruled the country with an iron fist for decades.

The NLD won Burma's last elections in 1990, but the military never allowed the party to take power and has since intimidated and arrested thousands opposed to military rule.

Aung San Suu Kyi is on trial for violating the terms of her house arrest for allowing an uninvited guest to stay at her home without official permission. She is expected to be sentenced to up to five years in prison.

Many of her supporters say Burma's military is using the trial to make sure she can be kept imprisoned next year. That way, she can not influence new elections the government is holding as part of its long-promised move toward democracy. The military-drafted constitution, however, grants the generals significant control over any elected government.